Stabilized aminophylline solution and process therefor

Abstract

A stable aqueous aminophylline solution is provided by admixing with said solution disodium edetate as a chelating agent and removing substantially all the carbon dioxide from the solution. In a preferred manner the chelating agent is present in an amount of 0.01 to 1.0% by weight of the solution. Carbon dioxide is preferably removed to optimize aminophylline stability by boiling the solution under an inert gas protection. A stabilized aqueous aminophylline solution results which can be packaged in a container system which would otherwise have a propensity to develop undesired crystal growth in the solution.

I claim: 
     
       1. A method of stabilizing and preventing undesired crystal growth in an aqueous aminophylline solution for contact with a container system tending to promote crystal growth comprising: forming a solution of aminophylline, water, and disodium edetate, said disodium edetate present in the amount of about 0.01 to about 1.0% by weight based on the total solution weight, admixing ethylenediamine to effect a pH in the resulting solution of about 8.6 to about 9.0, said water prior to mixing with said aminophylline and disodium edetate being substantially free of carbon dioxide and excluding substantially all carbon dioxide from said solution by means of inert gas protection, said disodium edetate chelating any metal ion being present in said solution to form a soluble material. 
     
     
       2. The method of claim 1 wherein said water is rendered free of carbon dioxide by boiling. 
     
     
       3. The method of claim 2 wherein said boiling is effected under an inert gas protection. 
     
     
       4. The method of claim 3 further including the filling of said container under inert gas protection. 
     
     
       5. The method as defined in claim 4 wherein said inert gas is nitrogen. 
     
     
       6. A stabilized aqueous aminophylline solution for contact with a container system tending to promote undesired crystal growth comprising: an aqueous aminophylline solution containing about 0.01 to about 1.0% by weight, based on the total solution weight, of disodium edetate as a chelating agent, said stabilized solution having removed therefrom substantially all carbon dioxide and including ethylenediamine to effect a pH of at least about 8.6 to about 9.0. 
     
     
       7. A stabilized aminophylline solution as defined in claim 6 wherein said solution further contains an inert gas.